STUDY OF EPISTATIC GENE ACTION USING TRIPLE TEST CROSS PROCEEDURE IN MAIZE

Abstract

Pure lines of maize: W13R, R153, W17.131, OH40, IK58, IK8, ZP and SH were crossed with three testers, Agr183, DK and (Agr183 x DK). Genotypes: (lines, testers and hybrids) were planted by using randomized complete block design with two replications for the deduction of epistasis, estimation of variance components and some genetical parameters for: plant height, upper ear height, ear diameter, ear length, No. rows per ear, 100-grain weight and grain yield per plant. Mean squares for genotypes, hybrids and parents (lines & testers) were highly significant for all traits. Analysis of variance for epistatic gene action test indicated non significant lines mean square for all traits which indicated the absence of epistasis. Additive and dominance variances were important for the inheritance of most traits. Broad sense heritability estimates was more than (90%) for all traits while narrow sense heritability ranged from (8.12%) for ear length to (80.85%) for ear diameter, and the genetic advance (as percent of the mean) was found to be high for No. rows per ear, low for ear length and moderate for the remaining characters. The negative simple correlation coefficients showed that there is increasing of dominant genes for upper ear height, ear diameter and ear length, while the positive correlation coefficients for other characters indicated the reverse.